


The Biological Imperative

by Anonymous



Category: Supernatural
Genre: Body Horror, Bottom Castiel, Changed!Winchesters, Crying Castiel, Gagged Castiel, Hurt Castiel, Hurt No Comfort, Impregnation, M/M, Multi, Non-Consensual Bondage, Non-Consensual Touching, Rape, The Winchesters betray Castiel, Tied-Up Castiel
Language: English
Status: Completed
Published: 2018-11-13
Updated: 2018-11-13
Packaged: 2019-08-23 08:18:49
Rating: Explicit
Warnings: Rape/Non-Con
Chapters: 1
Words: 917
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/16615313
Author URL: https://archiveofourown.org/
Summary: One too many trips through the rift changes Dean and Sam.It changes how they feel about Cas, too.But it’s too late for him now.





	The Biological Imperative

Neither of them can quite pinpoint when it started; it’s irrelevant anyway. What was _then_ doesn’t matter half as much as what’s _now_. 

It doesn’t matter at all. 

What does matter is the angel in Dean’s room, and what he means to them. 

It’s taken a lot of planning to reach this stage. Allaying the angel’s fears, for one thing. He’d argued with them each time they went back and forth between their dimension and the one through the rift; that humans weren’t meant to make that journey, at least not as many times as they had. 

But the change in them had been so gradual that it went unnoticed, even by him, and now...here they are. 

Finding hunts, concocting reasons to get everyone else out of the bunker for a while was tricky but they managed it. 

Jack was hardest; he wants to be where Cas is, like he thinks sticking close to his adopted dad now makes up for throwing him aside in favour of Lucifer. 

But Dean took care of that. Jack still fears him, and all it took was Dean suggesting Cas deserved a little breathing space away from the ungrateful little _prick_ to send Jack scampering after the rest of them. 

A little harsh, Sam thinks, but necessary. 

They need Cas alone for this. 

When the last of them is gone, they head back to Dean’s room. Cas flinches when they come in, but makes no sound (the duct tape fastened over his mouth, with the Enochian word for _silence_ written on it, has done its job well) and watches them with wary eyes as Dean takes a seat by the bed. 

Sam doesn’t. He strips slowly; shirt first, kicking off shoes next, removing his socks and then, finally, his jeans and underwear. 

It feels good to be free of them. The ever present ache trapped in clothing not designed to take into account his new dimensions. 

He hears the cry of surprise from the angel and can’t help but preen a little. The circumstances are less than ideal, but he can’t resist showing off a little for their mate. 

Dean snorts at his display. “We’ve already got him, dude. Quit acting like a damn peacock.”

Sam turns to glare at him. “Do you have to?”

Dean shrugs his annoyance off. “Just get a move on. If he catches, we’ll need to move fast.”

Sam looks back at the bound angel. “He’ll catch.” 

Cas fights as Sam strips him, tearing through cloth when he has to, working around the manacles restraining him, until Cas is as naked as him. It might be a while before they can let him have clothes again, he thinks as he climbs onto the bed. 

If Cas catches, any clothes they have will quickly be too small. If he doesn’t (unlikely since Sam has a real good feeling about this) then Cas might as well stay naked because they’ll have to do this again, mount him until it takes. 

And however it goes, Cas is going to be tied to something because Sam has another certain feeling that Cas is never going to just give up and let them do what they need to. 

When he’s settled between Cas’s legs, Sam scoops up some of his own slick. He works it carefully into the angel; the last thing he wants is for Cas to tear. The more unpleasant this is, the more Cas will resist. 

And Dean…. Dean’s not as patient as he is. 

When he’s satisfied, Sam slips the tapered tube just under his penis into Cas. It sinks deeper and hardens. Cas pants and makes muffled pleas. Sam soothes him as best he can but this part won’t be easy. 

He bears down, and the eggs, probably no more than three or four, since this is their first clutch, start their passage from him to their mate. 

By the time it’s done, Cas is shaking. His Grace is bound enough that while it’ll keep him healthy, it won’t make this process any easier. But with his Grace unhampered, there’s a good chance Cas could overpower them. And even if not, it might help him reject the eggs, even void them, or interfere with the fertilisation process. 

Speaking of…

Sam pulls out, and leans forward to press a kiss to Cas’s forehead, but the angel twists savagely away from him. 

That’s okay. It’s understandable he’d be upset. 

“Your turn,” he says and gets off the bed. 

Cas cries, actually cries, when Dean gets up next. He doesn’t bother stripping - doesn’t really have to - just undoes his fly and slides his dick out. 

The only difference from before is the barbed tip that will keep him locked inside until he’s flooded Cas with enough seed to get the job done. 

This is the bit Sam’s really worried about. If Cas tries to pull away, Dean’s dick will literally tear him open. 

He winces as Dean grabs Cas’s thighs and unforgivingly pulls Cas down onto his dick. 

The tape does little to silence Cas’s cries of pain. Sam holds him as he best he can, trying to comfort him when he knows it probably won’t help. 

What it does, though, is let him limit Cas’s struggles as Dean settles inside him and waits until his body’s done what it has to do. 

“Please, Cas,” Sam begs, as Cas trembles in his arms. “Hold on, okay? Your first time…. I think your first time will be the worst.”


End file.
